Cooler temperatures are helping firefighters battling a wildfire in southern California and an official says the blaze was expected to be fully under control within 24 hours.

The so-called Springs Fire has charred about 28,000 acres (11,300 hectares) of brush land in a coastal area northwest of Los Angeles since it started on Thursday (local time).

The favourable weather on Sunday helped firefighters as they put containment lines around the fire, which they estimate will be completely contained sometime on Monday.

"We're really not seeing a lot of fire activity out there right now," said Captain Dan Horgon of the Ventura County Fire Department.

"There are occasional flare-ups here and there, but with the weather, everything has really died down compared to a few days ago," he said.

By Sunday, the fire was 60 per cent contained, Horgon said.

The Springs Fire, and a flurry of smaller blazes around the state last week, marked a sudden start to the California fire season. Some weather forecasters have predicted the season will be worsened by a summer of higher temperatures and drought throughout much of the U.S. West.

About 4000 homes had been threatened by the fire but only 15 homes were reported to have been damaged, Horgon said. Seven people suffered minor injuries, including six firefighters, he said.

On Saturday, officials lifted evacuation orders and road closures in areas close to the fire.